With the way that tank stats are calculated in pvp they are all but useless. As a result Tanks in pvp tend to run a hybrid spec and/or stack dps stats. My proposal is that an additional effect is added to the fifth or sixth tier of the talent tree that converts defensive stats to pvp damage reduction. something along the lines of (defense chance + absorb amt) * shield chance for example if you have 20% defense and 40% absorb and 20% shield chance you would get .60 * .20 = .12 or 12% additional pvp damage reduction the same stats with 40% shield chance would yield .60 * .40 = .24 or 24% additional pvp damage reduction keeping it high in the talent tree would keep dps hybrids from being able to get to it and make tanking stats worthwhile. the additional reduction in damage taken would come at the cost of lower damage output (from having far less dps stats) making pvp tanking more similar to pve tanking where your job is to protect your group not to kill stuff.